Noninvasive in utero assessment of PR and QRS intervals from the fetal magnetocardiogram

Fetal cardiac waveform intervals were assessed from fetal magnetocardiogram (FMCG) recordings taken from 59 pregnant women at 17-41 weeks gestation. B eyond 27 weeks' gestation PR and QRS intervals, measured from averaged wave forms, could be obtained from all subjects; however, prior to 21 weeks' ges tation the success rare was 50% or less due to low signal-to-noise ratio. Q T interval could not be assessed accurately in most subjects. Weak, but sta tistically significant, correlations with gestational age were found for PR interval (n = 145, R-2 =0.033, P = 0.028) and QRS interval (n = 145, R-2 = 0.140, P <0.0005). Abnormal waveform morphology was documented in several patients with cardiac malformations. (C) 1999 Elsevier Science Inland Ltd. All rights reserved.